Ping for reply! 2013/12/25 Chuanbo Weng <strgnm@xxxxxxxxx>: > Hi all, > > (My environment is intel platform, HD4000 GPU, kernel 3.10.19, > logitech 270 webcam) > As title said, I discover this issue when I run the program > shown by Laurent Pinchart: > http://www.mail-archive.com/linux-media@xxxxxxxxxxxxxxx/msg54806.html > > If the frame is (width, height) = (640, 480), DMABUF works well. > If the frame is (width, height) = (160, 120), v4lfd receives no event. > > > And I dig into drm kernel code, find that: i915_gem_create will create > a GPU buffer object on intel platform. The size of GPU bo will be > bigger than frame size, for the reason that i915_gem_create will > roundup the bo size to multiple of PAGE_SIZE when the frame is (width, > height) = (160, 120). > For (width, height) = (640, 480), the frame size is already multiple > of PAGE_SIZE, so GPU bo is exactly equal to frame size. > > I also dump the uvc driver infomation, there is some infomation i > think maybe important: > uvcvideo: Stream 1 error event 07 01 len 4 > > Looking forward to the discussion! > > Thanks, > Chuanbo Weng -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
